A 2e children should be formally tested for a learning difficulty or disability and for giftedness.
If you think your child may have a learning difficulty or disability, you can request formal testing from your school by sending written communication to your school's administration & your child's teacher.
If you think your child may be gifted, you can request formal testing from your school. Formal testing for a learning difficulty or disability can happen any time of year. That is not always the case with testing for giftedness. Be sure to keep a look out as some schools only host the opportunity once a year due to the fact that assessing giftedness requires not just assessing the child but comparing the child's abilities to the abilities of their peers at that same moment.
Because 2e children typically perform inconsistently, it is important that the test used to determine giftedness is multi-dimensional. Only a combination of formal and informal assessments can accurately identify a twice-exceptional child.
Krochak & Ryan's research shows that formal testing to identify twice-exceptional children should include...
a written assessment such as The Wechsler Intelligence Scales for Children (WISC)
behavioral checklists completed by parents, teachers, & students
portfolio reviews of work samples